Is the D4's autofocus better than the 1DX's for very fast action shots? I currently shoot with a 5D Mark iii and have Canon glass. I've tried out all the AI servo cases and I consistently get blurry shots. I'm trying to shoot a very fast dog playing frisbee and maybe 1 out of every 100 shots is in focus. I'm using Canon's 70-200L 2.8 IS II USM lens.

However, I tried out a D4 and it was very good. The autofocus was better than my 5d as it should have been. I've read that Nikon tends to have better autofocus and Canon has better colors and lens selection. I also think Canon is better at macrophotography especially with it's macro flashes and the mpe-65mm 5x lens.

I'm completely willing to buy Nikon glass in order to have the best autofocus possible if in fact the Nikon D4 has better autofocus than the Canon 1DX. What do you think?